1. Field
The present invention relates to a load balancer having a band control function and a setting method thereof, and more particularly, to a load balancer in which a load balancing function setting and a band control function setting can be easily performed and a setting method thereof.
2. Description of the Related Art
A load balancer is an apparatus whose purposes are to avoid poor quality of a service provided by a plurality of servers due to centralized load thereon and to provide comfortable service to a client. More specifically, a load balancer forms a server group including a plurality of servers that provide the same service, and requests from a client are directed to servers in the server group, thereby reducing loads on the servers.
A band control apparatus is an apparatus whose purposes are to guarantee quality of a service having a higher priority than various other services provided by the servers whose band should not be strained and to limit a service having a lower priority. More specifically, a band control apparatus assigns an appropriate band to each communication line, thereby controlling a band used by each service.
Thus, a load balancer and a band control apparatus are used for improving quality of service. Therefore, they are often used in combination with each other. In recent years, an apparatus in which a load balancing function and a band control function are integrated is used.
Typically, when a load balancing function and a band control function are used in combination with each other, an administrator is required to first consider types of services to provide and performance of servers, then set up a load balancing function, predict the amount of a band used by each server, consider band control condition, and finally set up band control function. If, for example, the number of servers fluctuates, the settings are required to be reviewed and accordingly be performed again.
For example, if a server is added to or removed from a server group, a load balancing condition is required to be reviewed and a load balancing function is required to be set up again, as well as a band control condition is required to be reviewed and a band control function setting is required to be performed again so that traffic between a load balancing function and a server group is appropriate. If a server has a failure or is recovered therefrom, the number of servers also fluctuates. Therefore, a setting for a load balancing function and a band control function is required to be considered again. The consideration of appropriate settings for a load balancing function and band control function is a difficult task that requires knowledge and experience thereabout. The task is significant burden for an administrator.
To reduce such a load on an administrator, in Japanese Patent Application Laid-open No. 2003-124976, a technology for automatically correcting a band control condition is disclosed. According to the disclosed technology, if user load fluctuates in a data center, resources assigned to the user in accordance with the load can be dynamically modified, and security for the user can be secured.
In the conventional technology disclosed in Japanese Patent Application Laid-open No. 2003-124976, an administrator of a load balancer is required to perform initial setting of a load balancing function and a band control function in advance. Therefore, even if the conventional technology is used for the load balancer, the administrator is still required to consider the initial setting. Therefore, loads on the administrator who performs the initial setting are yet to be reduced.